OSHMEM: spml ikrit: hardware rdma endpoint

Create additional endpoint that is capable of true
one sided RDMA transfers.

MXM atomics component now uses this endpoint
(cherry picked from commit 1bcc88cfb1a0868e733802d343ddf16ffd2b93a0)
OSHMEM: spml ikrit: improve mxm transport sanity check

Do not allow combination of transports that is not compliant with
shmem spec. Especially do not allow mix of hw and software atomic
ops

(cherry picked from commit 74ab30b73855fdb4559ccdcdd4cae6545ac75236)
OSHMEM: spml ikrit: hw rdma channel is disabled by default
(cherry picked from commit 643e64497d531830111ed7a1ddf5bebceea9d4a3)
OSHMEM: spml ikrit: remove empty lines in helpfile
(cherry picked from commit 1f2ab43ba90734b99ffc9acf85a49ec9cf17b621)
OSHMEM: fixes 'improve mxm transport sanity check'

The code that actually checks for valid transport combos
somehow did not make it to the original commit:

74ab30b73855fdb4559ccdcdd4cae6545ac75236
(cherry picked from commit d06fb853500c3d3de4ba6521df34dcfa60bfa33c)
OSHMEM: spml ikrit: code style fixes

added missing {} around one line blocks in if()
OSHMEM: spml ikrit: use opal_setenv instead of setenv
Merge pull request #28 from alex-mikheev/topic/oshmem_spml_ikrit_hw_rdma_channel-v1.8

OSHMEM: spml ikrit: add hardware rdma endpoint